U.S. Pat. No. 4,488,608 describes a replaceable tooth article for a digging and breaking tool consisting of an adapter and the tooth. The article is used in a suction head of an excavator and can have a pyramidal outer shape modified with a rounded apex and a plurality of rounded edges. The replaceable tooth has a core composed of a low alloy, temperable and hardenable steel and is provided with a hard metal reinforcement (see also German Patent No. 31 36 077).
The tooth apex is provided with a hard metal, e.g. tungsten carbide, reinforcement constructed as a spike with a rounded tip and inserted in a cavity in the end of the core. Such a tooth is very sensitive to nonuniform tool engagement or operation.
The sides of the tooth, at least in the vicinity of the peak, are subjected to extensive wear. This also contributes to hard metal spike break off.